<http://schema.org/description>
"The World War I flight timeline chronicles the major milestones in aviation history during this time. This era saw the aviation industry rise rapidly in popularity. Check out the World War I flight timeline."^^<http://www.w3.org/2001/XMLSchema#string>
<http://science.howstuffworks.com/transport/flight/classic/world-war-i-flight-timeline7.htm>